U.S. patent number 11,289,726 [Application Number 16/675,986] was granted by the patent office on 2022-03-29 for systems for hybrid fuel cell power generation.
This patent grant is currently assigned to HONEYWELL INTERNATIONAL INC.. The grantee listed for this patent is HONEYWELL INTERNATIONAL INC.. Invention is credited to Dacong Weng, Daguang Zheng.
United States Patent |
11,289,726 |
Zheng , et al. |
March 29, 2022 |
Systems for hybrid fuel cell power generation
Abstract
A hybrid fuel cell system includes a fuel supply system
including a fuel tank, a start-up subsystem, a reforming subsystem
and a depressurization system. The reforming subsystem is to
receive fuel and to reform fuel to generate a hydrogen enriched
gases and steam mixture. The hybrid fuel cell system includes a
water supply system that provides water for the steam generator.
The water supply system includes a water condenser directly
downstream from the reforming subsystem that is in fluid
communication with the hydrogen enriched gases and steam mixture to
condense the hydrogen enriched gases and steam mixture into water
and hydrogen enriched gases. The depressurization system is to
reduce a pressure of the hydrogen enriched gases. The hybrid fuel
cell system includes a fuel cell stack downstream from the
depressurization system and having an anode inlet in fluid
communication with the depressurization system to receive the
hydrogen enriched gases.
Inventors: |
Zheng; Daguang (Torrance,
CA), Weng; Dacong (Rancho Palos Verdes, CA) |
Applicant: |
Name |
City |
State |
Country |
Type |
HONEYWELL INTERNATIONAL INC. |
Morris Plains |
NJ |
US |
|
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Assignee: |
HONEYWELL INTERNATIONAL INC.
(Charlotte, NC)
|
Family
ID: |
56296470 |
Appl.
No.: |
16/675,986 |
Filed: |
November 6, 2019 |
Prior Publication Data
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Document
Identifier |
Publication Date |
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US 20200075978 A1 |
Mar 5, 2020 |
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Related U.S. Patent Documents
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Application
Number |
Filing Date |
Patent Number |
Issue Date |
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14734921 |
Jun 9, 2015 |
10522860 |
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Current U.S.
Class: |
1/1 |
Current CPC
Class: |
H01M
8/04225 (20160201); H01M 8/0618 (20130101); H01M
8/04089 (20130101); H01M 8/0662 (20130101); H01M
8/04111 (20130101); C01B 3/48 (20130101); C01B
3/384 (20130101); H01M 8/0606 (20130101); H01M
8/0612 (20130101); F01D 15/10 (20130101); H01M
8/04007 (20130101); H01M 8/06 (20130101); Y02T
90/40 (20130101); C01B 2203/1685 (20130101); H01M
8/2457 (20160201); H01M 2250/402 (20130101); H01M
8/04753 (20130101); Y02T 10/30 (20130101); H01M
2250/20 (20130101); C01B 2203/0495 (20130101); C01B
2203/0233 (20130101); C01B 2203/0811 (20130101); C01B
2203/0894 (20130101); Y02E 60/50 (20130101); C01B
2203/169 (20130101); H01M 2250/407 (20130101); C01B
2203/066 (20130101); Y02B 90/10 (20130101) |
Current International
Class: |
H01M
8/0612 (20160101); H01M 8/04111 (20160101); H01M
8/04089 (20160101); C01B 3/48 (20060101); C01B
3/38 (20060101); H01M 8/04225 (20160101); H01M
8/04007 (20160101); H01M 8/0606 (20160101); H01M
8/06 (20160101); H01M 8/2457 (20160101); H01M
8/04746 (20160101); F01D 15/10 (20060101); H01M
8/0662 (20160101) |
References Cited
[Referenced By]
U.S. Patent Documents
Foreign Patent Documents
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2904476 |
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Feb 2008 |
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FR |
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07320763 |
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Dec 1995 |
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JP |
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Other References
Machine Translation of JP H07-320763 (Apr. 23, 2021) (Year: 2021).
cited by examiner .
Extended EP Search Report for Application No. 16172332.5-1373 dated
Oct. 20, 2016. cited by applicant.
|
Primary Examiner: Merkling; Matthew J
Attorney, Agent or Firm: Lorenz & Kopf, LLP
Parent Case Text
CROSS-REFERENCE TO RELATED APPLICATION
This application is a continuation of U.S. patent application Ser.
No. 14/734,921 filed on Jun. 9, 2015. The relevant disclosure of
the above application is incorporated herein by reference.
Claims
What is claimed is:
1. A hybrid fuel cell system comprising: a fuel supply system
including a fuel tank including a combustible fuel, a start-up
subsystem, a reforming subsystem and a depressurization system, the
start-up subsystem including a steam generator downstream from the
fuel tank that is configured to receive the fuel from the fuel tank
and to generate steam to raise an operating temperature of the
reforming subsystem, and the reforming subsystem is configured to
receive the fuel from the fuel tank and to reform the fuel from the
fuel tank to generate a hydrogen enriched gases and steam mixture;
a water supply system having a source of water that provides water
for the steam generator, the water supply system including a water
condenser directly downstream from the reforming subsystem that is
in fluid communication with the hydrogen enriched gases and steam
mixture, the water condenser is configured to condense the hydrogen
enriched gases and steam mixture into water and hydrogen enriched
gases, the water condensed by the water condenser is configured to
be communicated back to the source of water and the
depressurization system is downstream from the water condenser and
in fluid communication with the water condenser to receive the
hydrogen enriched gases; the depressurization system configured to
reduce a pressure of the hydrogen enriched gases, the
depressurization system including a turbine downstream from the
reforming subsystem to receive the hydrogen enriched gases and to
reduce the pressure of the hydrogen enriched gases and a heat
exchanger and a water condenser assembly that is configured to
receive the hydrogen enriched gases, the hydrogen enriched gases at
the reduced pressure from the turbine, and to condense water in the
hydrogen enriched gases with the hydrogen enriched gases at the
reduced pressure; and a fuel cell stack downstream from the
depressurization system and having an anode inlet in fluid
communication with the depressurization system to receive the
hydrogen enriched gases at the reduced pressure.
2. The hybrid fuel cell system of claim 1, wherein the
depressurization system includes a generator coupled to the turbine
to generate electrical energy as the turbine reduces the pressure
of the hydrogen enriched gases.
3. The hybrid fuel cell system of claim 1, further comprising: a
gas supply system in fluid communication with the fuel cell stack
to supply the fuel cell stack with a gas.
4. The hybrid fuel cell system of claim 3, further comprising a
heat exchanger upstream from the fuel cell stack configured to heat
the gas from the gas supply system.
5. The hybrid fuel cell system of claim 1, wherein the reforming
subsystem further comprises: a mixing valve in direct fluid
communication with the fuel pump to receive fuel from the fuel tank
and in direct fluid communication with the steam generator to
receive the steam heated by the steam generator, the mixing valve
configured to combine the fuel with the steam to create a mixture
of fuel and steam; a reformer in fluid communication with the
mixing valve to receive the mixture of fuel and the steam; and a
water-gas shift reactor in fluid communication with the reformer to
receive a hydrogen enriched gases and steam mixture from the
reformer.
6. The hybrid fuel cell system of claim 1, wherein the steam
generator is downstream from the fuel cell stack to combust one or
more exhaust gases from the fuel cell stack.
7. The hybrid fuel cell system of claim 1 further comprising a heat
exchanger downstream from the steam generator and upstream from the
fuel cell stack to receive the exhaust gas from the steam generator
and to heat the gas stream from the gas supply system before the
gas stream flows into the fuel cell stack.
8. A hybrid fuel cell system comprising: a fuel supply system
including a fuel tank including a combustible fuel, a start-up
subsystem, a reforming subsystem and a depressurization system, the
start-up subsystem including a steam generator downstream from the
fuel tank that is configured to receive the fuel from the fuel tank
and to generate steam to raise an operating temperature of the
reforming subsystem, and based on an operating temperature of the
reforming subsystem, the reforming subsystem is configured to
receive the fuel from the fuel tank and reform the fuel from the
fuel tank to generate a hydrogen enriched gases and steam mixture;
a water supply system having a source of water that provides water
for the steam generator, the water supply system including a water
condenser directly downstream from the reforming subsystem that is
in fluid communication with the hydrogen enriched gases and steam
mixture, the water condenser is configured to condense the hydrogen
enriched gases and steam mixture into water and hydrogen enriched
gases, the water condensed by the water condenser is configured to
be communicated back to the source of water; the depressurization
system is downstream from the water condenser and in fluid
communication with the water condenser to receive the hydrogen
enriched gases, the depressurization system is configured to reduce
a pressure of the hydrogen enriched gases, the depressurization
system includes a turbine downstream from the reforming subsystem
to receive the hydrogen enriched gases and to reduce the pressure
of the hydrogen enriched gases, a heat exchanger and a water
condenser assembly that is configured to receive the hydrogen
enriched gases, the hydrogen enriched gases at the reduced pressure
from the turbine, and to condense water in the hydrogen enriched
gases with the hydrogen enriched gases at the reduced pressure; and
a fuel cell stack downstream from the depressurization system and
having an anode inlet in fluid communication with the
depressurization system to receive the hydrogen enriched gases at
the reduced pressure.
9. The hybrid fuel cell system of claim 8, wherein the reforming
subsystem further comprises: a reformer in fluid communication with
the fuel tank and the steam; and a water-gas shift reactor in fluid
communication with the reformer to receive a hydrogen enriched
gases and steam mixture from the reformer.
10. The hybrid fuel cell system of claim 8, wherein the steam
generator is configured to receive the fuel from the fuel tank
based on a start-up command for the fuel cell system.
11. The hybrid fuel cell system of claim 8 further comprising a gas
supply system in fluid communication with the fuel cell stack to
supply the fuel cell stack with a gas and a heat exchanger upstream
from the fuel cell stack configured to heat the gas from the gas
supply system, the heat exchanger downstream from the steam
generator and upstream from the fuel cell stack, and the heat
exchanger configured to receive an exhaust gas from the steam
generator to heat the gas from the gas supply system before the gas
flows into the fuel cell stack.
Description
TECHNICAL FIELD
The present disclosure generally relates to systems for power
generation, and more particularly relates to power generation using
a hybrid fuel cell.
BACKGROUND
Generally, fuel cell systems employ a hydrogen-rich gas for power
generation. Certain fuels, while rich in hydrogen, may also have
heavy hydrocarbon compounds, such as diesel, jet fuel, etc. Fuels
with heavy hydrocarbon compounds may require reforming to generate
the hydrogen-rich gas for use by the fuel cell system. Certain
methods for reforming can involve the use of a steam reformer,
which can require an external heat transfer device to provide heat
to the steam reformer. The use of an external heat transfer device,
however, may add undesirable weight to the fuel cell system.
In addition, certain hybrid fuel cell systems require operation at
a high pressure. In order to operate these hybrid fuel cell systems
at a high pressure, a fuel cell stack associated with the fuel cell
system requires a reinforced structure to maintain the high
operating pressure. The use of the reinforced structure also adds
undesirable weight to the fuel cell system.
Accordingly, it is desirable to provide improved systems for hybrid
fuel cell power generation, which reduces system weight while
maintaining efficient power generation. Furthermore, other
desirable features and characteristics of the present invention
will become apparent from the subsequent detailed description and
the appended claims, taken in conjunction with the accompanying
drawings and the foregoing technical field and background.
SUMMARY
According to various embodiments, a hybrid fuel cell system is
provided. The hybrid fuel cell system includes a fuel supply
system. The fuel supply system includes a fuel source, a reforming
subsystem and a depressurization system. The fuel source is in
fluid communication with the reforming subsystem. The reforming
subsystem reforms the fuel from the fuel source to generate
hydrogen enriched gases, and the reforming subsystem is in fluid
communication with the depressurization system. The
depressurization system reduces a pressure of the hydrogen enriched
gases. The hybrid fuel cell system also includes a fuel cell stack
in communication with the depressurization system to receive the
hydrogen enriched gases at the reduced pressure.
A hybrid fuel cell system is provided, according to various
embodiments. The hybrid fuel cell system includes a fuel supply
system. The fuel supply system includes a fuel source, a start-up
subsystem, a reforming subsystem and a depressurization system. The
fuel source is in fluid communication with the start-up subsystem
and the reforming subsystem. The start-up subsystem includes a
steam generator that combusts the fuel from the fuel source and a
source of water. The steam generator combusts the fuel to heat the
water and generate steam. The reforming subsystem reforms the fuel
from the fuel source with the steam to generate a hydrogen enriched
gases and steam mixture. The depressurization system receives
hydrogen enriched gases and reduces a pressure of the hydrogen
enriched gases. The hybrid fuel cell system also includes a fuel
cell stack downstream from and in communication with the
depressurization system to receive the hydrogen enriched gases at
the reduced pressure. The fuel cell stack is upstream from the
steam generator.
Also provided according to various embodiments is a hybrid fuel
cell system. The hybrid fuel cell system includes a source of a gas
and a fuel supply system. The fuel supply system includes a fuel
source, a start-up subsystem, a reforming subsystem and a
depressurization system. The fuel source is in fluid communication
with the start-up subsystem and the reforming subsystem. The
start-up subsystem includes a steam generator that combusts the
fuel from the fuel source and a source of water. The steam
generator combusts the fuel to heat the water and generate steam.
The reforming subsystem reforms the fuel from the fuel source with
the steam to generate a hydrogen enriched gases and steam mixture.
The depressurization system receives hydrogen enriched gases and
reduces a pressure of the hydrogen enriched gases. The hybrid fuel
cell system also includes a fuel cell stack downstream from and in
communication with the depressurization system to receive the
hydrogen enriched gases at the reduced pressure. The fuel cell
stack is in communication with the gas supply system to receive the
gas. The steam generator is downstream from the fuel cell stack to
combust one or more exhaust gases from the fuel cell stack. The
hybrid fuel cell system also includes a heat exchanger downstream
from the steam generator and upstream from the fuel cell stack that
receives an exhaust gas from the burner and heats the gas from the
source of the gas before the gas flows into the fuel cell
stack.
Further provided is a hybrid fuel cell system. The hybrid fuel cell
system includes a fuel supply system including a fuel tank
including a combustible fuel, a start-up subsystem, a reforming
subsystem and a depressurization system. The start-up subsystem
includes a steam generator downstream from the fuel tank that is
configured to receive the fuel from the fuel tank and to generate
steam to raise an operating temperature of the reforming subsystem.
The reforming subsystem is configured to receive the fuel from the
fuel tank and to reform the fuel from the fuel tank to generate a
hydrogen enriched gases and steam mixture. The hybrid fuel cell
system includes a water supply system having a source of water that
provides water for the steam generator. The water supply system
includes a water condenser directly downstream from the reforming
subsystem that is in fluid communication with the hydrogen enriched
gases and steam mixture. The water condenser is configured to
condense the hydrogen enriched gases and steam mixture into water
and hydrogen enriched gases, and the water condensed by the water
condenser is communicated back to the source of water. The
depressurization system is downstream from the water condenser and
in fluid communication with the water condenser to receive the
hydrogen enriched gases. The depressurization system is configured
to reduce a pressure of the hydrogen enriched gases. The hybrid
fuel cell system includes a fuel cell stack downstream from the
depressurization system and having an anode inlet in fluid
communication with the depressurization system to receive the
hydrogen enriched gases at the reduced pressure.
Also provided is a hybrid fuel cell system. The hybrid fuel cell
system includes a fuel supply system including a fuel tank
including a combustible fuel, a start-up subsystem, a reforming
subsystem and a depressurization system. The start-up subsystem
includes a steam generator downstream from the fuel tank that is
configured to receive the fuel from the fuel tank and to generate
steam to raise an operating temperature of the reforming subsystem.
Based on an operating temperature of the reforming subsystem, the
reforming subsystem is configured to receive the fuel from the fuel
tank and to reform the fuel from the fuel tank to generate a
hydrogen enriched gases and steam mixture. The hybrid fuel cell
system includes a water supply system having a source of water that
provides water for the steam generator. The water supply system
includes a water condenser directly downstream from the reforming
subsystem that is in fluid communication with the hydrogen enriched
gases and steam mixture. The water condenser is configured to
condense the hydrogen enriched gases and steam mixture into water
and hydrogen enriched gases and the water condensed by the water
condenser is communicated back to the source of water. The
depressurization system is downstream from the water condenser and
in fluid communication with the water condenser to receive the
hydrogen enriched gases. The depressurization system is configured
to reduce a pressure of the hydrogen enriched gases. The hybrid
fuel cell system includes a fuel cell stack downstream from the
depressurization system and having an anode inlet in fluid
communication with the depressurization system to receive the
hydrogen enriched gases at the reduced pressure.
Further provided is a hybrid fuel cell system. The hybrid fuel cell
system includes a source of a gas, and a fuel supply system. The
fuel supply system includes a fuel source, a start-up subsystem, a
reforming subsystem and a depressurization system. The fuel source
is in fluid communication with the start-up subsystem and the
reforming subsystem. The start-up subsystem incldues a steam
generator downstream from the fuel tank that is configured to
receive the fuel from the fuel tank and to generate steam to raise
an operating temperature of the reforming subsystem. Based on an
operating temperature of the reforming subsystem, the reforming
subsystem is configured to receive the fuel from the fuel tank and
to reform the fuel from the fuel tank to generate a hydrogen
enriched gases and steam mixture. The depressurization system
receives hydrogen enriched gases and is configured to reduce a
pressure of the hydrogen enriched gases. The hybrid fuel cell
system includes a water supply system having a source of water that
provides water for the steam generator. The water supply system
includes a water condenser directly downstream from the reforming
subsystem that is in fluid communication with the hydrogen enriched
gases and steam mixture. The water condenser is configured to
condense the hydrogen enriched gases and steam mixture into water
and hydrogen enriched gases, and the water condensed by the water
condenser is communicated back to the source of water. The hybrid
fuel cell system includes a fuel cell stack downstream from the
depressurization system and having an anode inlet in fluid
communication with the depressurization system to receive the
hydrogen enriched gases at the reduced pressure. The fuel cell
stack is in communication with the gas supply system to receive the
gas, and the steam generator is downstream from the fuel cell stack
to combust one or more exhaust gases from the fuel cell stack.
DESCRIPTION OF THE DRAWINGS
The exemplary embodiments will hereinafter be described in
conjunction with the following drawing figures, wherein like
numerals denote like elements, and wherein:
FIG. 1 is a schematic illustration of a hybrid fuel cell system in
accordance with various embodiments;
FIG. 2 is a schematic illustration of a hybrid fuel cell system in
accordance with various embodiments; and
FIG. 3 is a schematic illustration of a hybrid fuel cell system in
accordance with various embodiments.
DETAILED DESCRIPTION
The following detailed description is merely exemplary in nature
and is not intended to limit the application and uses. Furthermore,
there is no intention to be bound by any expressed or implied
theory presented in the preceding technical field, background,
brief summary or the following detailed description. In addition,
those skilled in the art will appreciate that embodiments of the
present disclosure may be practiced in conjunction with any power
generation system that employs a hybrid fuel cell, and that the
hybrid fuel cell system described herein is merely one exemplary
embodiment according to the present disclosure. Moreover, while the
hybrid fuel cell system is described herein as being used onboard a
mobile platform, such as a bus, motorcycle, train, motor vehicle,
marine vessel, aircraft, rotorcraft and the like, the various
teachings of the present disclosure can be used with a stationary
hybrid fuel cell system as well. Further, it should be noted that
many alternative or additional functional relationships or physical
connections may be present in an embodiment of the present
disclosure. As used herein, the term module refers to any hardware,
software, firmware, electronic control component, processing logic,
and/or processor device, individually or in any combination,
including without limitation: application specific integrated
circuit (ASIC), an electronic circuit, a processor (shared,
dedicated, or group) and memory that executes one or more software
or firmware programs, a combinational logic circuit, and/or other
suitable components that provide the described functionality.
With reference to FIG. 1, a hybrid fuel cell system 10 is shown.
The hybrid fuel cell system 10 includes a fuel supply system 12, a
gas supply system 14, a water supply system 15, a fuel cell stack
16 and a control system 18. The hybrid fuel cell system 10 can be
part of a mobile platform 8, such as a bus, motorcycle, train,
motor vehicle, marine vessel, aircraft, rotorcraft and the like. In
the following example, the mobile platform 8 is described herein as
being an aircraft, however, it will be appreciated that the present
teachings of the present disclosure can be applied to any suitable
mobile platform and/or a stationary hybrid fuel cell system.
Although the fuel supply system 12, the gas supply system 14 and
the fuel cell stack 16 are illustrated herein as being contained
within or located onboard the mobile platform 8, it will be
understood that one or more (or a portion) of the fuel supply
system 12 and the gas supply system 14 can be located remote from
the mobile platform 8, if desired. As will be discussed, the fuel
supply system 12 does not require an external heat transfer device
while having improved heat transfer efficiency, and thereby
provides a hybrid fuel cell system 10 with reduced weight.
Moreover, the hybrid fuel cell system 10 includes the fuel cell
stack 16 operating at a low or ambient pressure, thereby further
resulting in mass savings for the hybrid fuel cell system 10. In
addition, while the figures shown herein depict an example with
certain arrangements of elements, additional intervening elements,
devices, features, or components may be present in an actual
embodiment. It should also be understood that FIG. 1 is merely
illustrative and may not be drawn to scale. Furthermore, while
certain conduits are illustrated herein for enabling fluid
communication between various components of the hybrid fuel cell
system 10, it will be understood that the arrangement illustrated
herein is merely exemplary. In this regard, any number of conduits
and valves can be employed to provide fluid communication or fluid
coupling between the various components of the hybrid fuel cell
system 10 as known to one skilled in the art. Thus, the arrangement
of conduits and valves contained herein is merely exemplary.
In addition, for the sake of brevity, conventional techniques
related to signal processing, data transmission, signaling,
control, and other functional aspects of the systems (and the
individual operating components of the systems) may not be
described in detail herein. Furthermore, the connecting lines shown
in the various figures contained herein are intended to represent
example functional relationships and/or physical couplings between
the various elements. It should be noted that many alternative or
additional functional relationships or physical connections may be
present in an embodiment of the present disclosure.
With continued reference to FIG. 1, the fuel supply system 12 is in
fluid communication with the fuel cell stack 16 to provide the fuel
cell stack 16 with a hydrogen-rich fuel supply or a supply of
hydrogen enriched gases. In one example, the fuel supply system 12
includes a fuel source 20, a fuel pump 22, a start-up subsystem 24,
a reforming subsystem 26 and a depressurization subsystem 28.
The fuel source 20 can comprise any suitable source of hydrogen
containing fuel. In one example, the fuel source 20 can be disposed
within the mobile platform 8, and can comprise a fuel tank, which
can be fillable with a suitable hydrogen containing fuel. In the
example of an aircraft, the fuel source 20 can comprise one or more
of the wing mounted fuel tanks and/or a center mounted tank
associated with the aircraft. The fuel contained in the fuel source
20 can comprise hydrogen, generally in the form of hydrocarbons. In
one example, the fuel source 20 can comprise a source of jet fuel.
In one example, the fuel source 20 can comprise a source of jet
fuel. Exemplary jet fuels can comprise Jet A, Jet A-1 and Jet B. In
order to optimize the performance of the fuel cell stack 16, fuel
from the fuel source 20 is in communication with the reforming
subsystem 26 to generate hydrogen-rich or hydrogen enriched gas
from the fuel. Fuel from the fuel source 20 is also in fluid
communication with the start-up subsystem 24 to provide the
start-up subsystem 24 with fuel for initializing the hybrid fuel
cell system 10 as will be discussed in greater detail herein.
The fuel pump 22 is in communication with the fuel source 20. While
the fuel pump 22 is illustrated herein as being in communication
with the fuel source 20 via a conduit 30, the fuel pump 22 can be
disposed in the fuel source 20 (e.g. located within a fuel tank).
The fuel pump 22 comprises any suitable fuel pump, including, but
not limited to a diaphragm pump, a positive displacement pump, a
piston metering pump, centrifugal pump, etc., as known to one
skilled in the art. As the fuel pump 22 can be known to those
skilled in the art, the fuel pump 22 will not be discussed in great
detail herein. Briefly, the fuel pump 22 is operable to draw fuel
from the fuel source 20 and deliver the fuel to the start-up
subsystem 24 via conduit 32 and/or the reforming subsystem 26 via a
conduit 34. It should be noted that while two conduits 32, 34 are
illustrated herein, any arrangement of conduits and valves,
including a single conduit with a three-way valve, for example. In
one example, the fuel pump 22 is responsive to one or more control
signals from the control system 18 to draw the fuel from the fuel
source 20.
The start-up subsystem 24 receives fuel from the fuel source 20 via
the fuel pump 22. The start-up subsystem 24 uses the fuel from the
fuel source 20 to generate heat to bring the reforming subsystem 26
to a desired operating temperature. In one example, the start-up
subsystem 24 comprises a start-up valve 36 and a steam generator or
burner 38. The start-up valve 36 is coupled to the conduit 32 and
is operable to permit or prevent the flow of fluid from the conduit
32 into the steam generator or burner 38. The start-up valve 36 can
comprise any suitable valve capable of controlling a fluid flow as
known to one skilled in the art. In one example, the start-up valve
36 comprises an electrically actuatable valve, which is responsive
to one or more control signals from the control system 18 to move
the start-up valve 36 between a first, opened position that enables
fuel to flow to the steam generator or burner 38 and a second,
closed position that prevents the flow of fuel into the steam
generator or burner 38. The start-up valve 36 is illustrated herein
as being coupled to the conduit 32 and a conduit 40, with the
conduit 40 fluidly coupling the start-up valve 36 to the steam
generator or burner 38; however, the start-up valve 36 can be
coupled directly to an inlet port 42 of the steam generator or
burner 38, if desired.
The steam generator or burner 38 includes the inlet port 42, an
inlet port 44, an inlet port 46, a water inlet 48, a water outlet
50, an exhaust outlet 52 and a combustion source 54. The steam
generator or burner 38 operates to combust fluids and/or gases
received via the inlet ports 42, 44, 46 to generate heat to convert
water received via the water inlet 48 into steam that exits the
steam generator or burner 38 at the water outlet 50 and heated
exhaust gas that exits the steam generator or burner 38 at the
exhaust outlet 52. The steam generator or burner 38 can comprise
any suitable fuel cell afterburner, combustor or catalytic
combustor known to one skilled in the art. Generally, the steam
generator or burner 38 operates at a low or an ambient
pressure.
At the inlet port 42, the steam generator or burner 38 is fluidly
coupled to the fuel pump 22 to receive fuel from the fuel source 20
when the start-up valve 36 is in the first, opened position. At the
inlet port 44, the steam generator or burner 38 is fluidly coupled
to the fuel cell stack 16 via a conduit 56 to receive exhaust gases
associated with a cathode 58 of the fuel cell stack 16. Generally,
the exhaust gases associated with the cathode 58 comprise air. At
the inlet port 46, the steam generator or burner 38 is fluidly
coupled to the fuel cell stack 16 via a conduit 60 to receive
exhaust gases associated with an anode 62 of the fuel cell stack
16. Generally, the exhaust gases associated with the anode 62
comprise hydrogen depleted fuel gas.
At the water inlet 48, the steam generator or burner 38 receives
water via a conduit 64. As will be discussed further herein, the
conduit 64 is also fluidly coupled to the reforming subsystem 26
and to the water supply system 15 to provide water to the water
inlet 48. In one example, a conduit 66 is in communication with the
conduit 64. The conduit 66 continues through or passes through the
steam generator or burner 38 such that the water within the conduit
66 is heated by the combustion occurring within the steam generator
or burner 38 to convert the water into steam prior to the conduit
64 exiting the steam generator or burner 38 at the water outlet 50.
At the water outlet 50, the water that has entered the steam
generator or burner 38 at the water inlet 48 has been converted
into high temperature steam. Thus, the conduit 66 enables heat
transfer between the steam generator or burner 38 and the water
within the conduit 66. The water outlet 50 is fluidly coupled to
the conduit 66 and the reforming subsystem 26 via a conduit 68 to
supply the reforming subsystem 26 with the high temperature steam.
It should be noted that while three conduits 64, 66, 68 are
described herein, the conduits 64, 66, 68 can comprise a single
conduit and one or more valves that enable fluid communication
between the reforming subsystem 26 and the steam generator or
burner 38.
The exhaust outlet 52 is in fluid communication with a portion of
the gas supply system 14, as will be discussed in greater detail
herein. Briefly, the exhaust outlet 52 is in communication with a
conduit 70 that receives hot exhaust gases generated by the
combustion process within the steam generator or burner 38 and the
conduit 70 carries these hot exhaust gases through a heat exchanger
72 associated with the gas supply system 14. As will be discussed,
the heat exchanger 72 operates to transfer the heat from the
exhaust gases to gas supplied by the gas supply system 14 to raise
the temperature of the gas supply system 14 and thereby cool or
reduce the temperature of the exhaust gas. Once the exhaust gases
have passed through the heat exchanger 72, the exhaust gases are
expelled or exhausted outside of the mobile platform 8.
The combustion source 54 can comprise any suitable source for
igniting the fluid and/or gases received at the inlet ports 42, 44,
46. In one example, the combustion source 54 comprises a spark
igniter, however, the combustion source 54 can comprise any
suitable igniter known to one skilled in the art, including, but
not limited to, the spark igniter, a hot surface type igniter and a
catalytic combustor type igniter. In one example, as is generally
known, the steam generator or burner 38 can comprise a combustion
chamber 38a, through which the conduit 66 containing water can
pass. The inlet ports 42, 44, 46 are in communication with the
combustion chamber 38a to provide the combustion chamber 38a with
the fluids and/or gases for combustion. The combustion source 54
can be disposed in the combustion chamber 38a to ignite the fuels
and/or gases received from the inlet ports 42, 44, 46 to generate
heat. As the conduit 66 passes through the combustion chamber 38a
so as to be in proximity to the heat generated by the combustion
process, the heat from the combustion process converts the water
which enters the conduit 66 at the water inlet 48 into steam, which
exits the combustion chamber 38a and the steam generator or burner
38 at the water outlet 50 and is directed via the conduit 68 to the
reforming subsystem 26. Thus, the steam generator or burner 38
serves to generate steam, which can be used by the reforming
subsystem 26.
The reforming subsystem 26 is fluidly coupled to the steam
generator or burner 38 and the fuel pump 22. The reforming
subsystem 26 reforms the fuel from the fuel source 20 (provided by
the fuel pump 22) to generate a high pressure hydrogen-rich gas or
hydrogen enriched gases for use by the fuel cell stack 16. In one
example, the reforming subsystem 26 includes a mixing valve 74, a
reformer 76 and a water-gas shift reactor 78. The mixing valve 74
is in fluid communication with the conduit 34 to receive fuel from
the fuel source 20 and is in fluid communication with the conduit
68 to receive high temperature steam heated by the steam generator
or burner 38. The mixing valve 74 comprises any suitable valve
known to one skilled in the art that enables the mixing of the fuel
with the high temperature steam. Generally, the mixing valve 74
combines the fuel from the conduit 34 with the high temperature
steam from the conduit 68 at a desired fuel/steam ratio, and the
mixture of fuel and high temperature steam flows out of the mixing
valve 74 into a conduit 80.
The conduit 80 is in fluid communication with the reformer 76. In
one example, the reformer 76 comprises any suitable steam reformer
known to those skilled in the art. For example, the reformer 76
comprises a steam reformer catalyst. As the reformer 76 is
generally known in the art, the reformer 76 will not be discussed
in great detail herein. Briefly, however, the reformer 76 includes
a reformer inlet 82, an optional air inlet 84, a reformer outlet 86
and a housing 88. The reformer inlet 82 is in fluid communication
with the conduit 80 to receive the mixture of high temperature
steam and fuel from the mixing valve 74. The air inlet 84 is in
fluid communication with a source of air, such as ambient air
within the mobile platform 8, or air external to the mobile
platform 8. The reformer outlet 86 is in fluid communication with a
conduit 90 to direct the product of the steam reformer to the
water-gas shift reactor 78.
The reformer inlet 82, optional air inlet 84 and reformer outlet 86
are each coupled to and in fluid communication with the housing 88
of the reformer 76. The housing 88 generally contains a reactant or
catalysts 88a that facilitate a reaction between the high
temperature steam and fuel. The catalysts 88a can comprise a base
metal catalyst, which can be contained in the housing 88. The
catalysts 88a can be disposed in the housing 88 in any suitable
fashion to facilitate the reaction between the high temperature
steam and fuel, and in one example, the catalysts 88a can form a
packed bed, over which the high temperature steam and fuel can
flow. The reaction between the high temperature steam and fuel
converts the fuel into hydrogen (H.sub.2), carbon monoxide (CO) and
carbon dioxide (CO.sub.2), which flows with the steam from the
reformer outlet 86 associated with the housing 88 via the conduit
90. Generally, the reformer 76 operates at a pressure that is
higher than ambient pressure, such as about 1.0 barG to about 10.0
barG.
Table 1, below, illustrates a simulation of the reformation of jet
fuel in the reformer 76.
TABLE-US-00001 TABLE 1 steam inlet steam/fuel Reactor dry based T
(C.) ratio T (C.) CO2 % H2O % H2 % CO % CO % Fuel Content 900 2
564.42 8.15 6.93 65.67 19.08 20.51 After Reformer 900 3 642.64
10.72 19.16 58.21 11.77 14.56 900 4 689.40 10.84 29.44 51.29 8.32
11.79 900 5 722.10 10.38 37.61 45.61 6.30 10.10 900 6 745.73 9.80
44.14 41.00 4.97 8.90
In Table 1, the steam inlet temperature in degrees Celsius (C) is
the temperature at the reformer inlet 82, and the reactor
temperature is a temperature of the housing 88 of the reformer 76.
The steam/fuel ratio is the ratio of steam to fuel as mixed by the
mixing valve 74. The values of the percentage of carbon dioxide
(CO.sub.2), water (H.sub.2O), hydrogen (H.sub.2), carbon monoxide
(CO) and dry based carbon monoxide (dry based CO) are determined
after the jet fuel and steam mixture has passed through the
reformer 76. In this simulation, the reformer 76 is operating at a
pressure of 1 atmosphere (atm).
The conduit 90 is coupled to and in fluid communication with the
water-gas shift reactor 78. The water-gas shift reactor 78 can
comprise a suitable water-gas shift reactor catalyst, as known to
one skilled in the art. Generally, the water-gas shift reactor 78
operates at a pressure that is higher than ambient pressure, such
as about 1.0 barG to about 10.0 barG. As the water-gas shift
reactor 78 is known to one skilled in the art, the water-gas shift
reactor 78 will not be discussed in great detail herein.
Briefly, however, the water-gas shift reactor 78 includes a reactor
inlet 92, a reactor water inlet 94, a reactor water outlet 96, a
reactor outlet 98 and a housing 100. The reactor inlet 92, reactor
water inlet 94, reactor water outlet 96 and the reactor outlet 98
are each coupled to and in fluid communication with the housing
100. In one example, the housing 100 of the water-gas shift reactor
78 includes a fixed bed reactor having catalysts that convert the
carbon monoxide (CO) and steam received at the reactor inlet 92
from the conduit 90 into hydrogen (H.sub.2) and carbon dioxide
(CO.sub.2), resulting in hydrogen enriched gases and steam at the
reactor outlet 98.
The reactor inlet 92 is fluidly coupled to the conduit 90 to
receive hydrogen (H.sub.2), carbon monoxide (CO) and carbon dioxide
(CO.sub.2) gas, and steam from the reformer 76. The reactor water
inlet 94 is in communication with the water supply system 15 to
receive low temperature water from the water supply system 15 for
circulation within the housing 100 via a conduit 95. The
circulation of the low temperature water within the housing 100
from the reactor water inlet 94 to the reactor water outlet 96 via
the conduit 95 can allow for slight heat transfer between the gas
received from the reformer 76 and the water received from the water
supply system 15. The water circulated through the housing 100
exits the housing 100 at the reactor water outlet 96, which is
coupled to and in fluid communication with the conduit 64 to direct
this water to the steam generator or burner 38. The reactor outlet
98 is coupled to and in fluid communication with a conduit 102, and
the conduit 102 directs the resultant hydrogen enriched gases and
steam from the water-gas shift reactor 78 to a water condenser 104
associated with the water supply system 15. As will be discussed in
further detail below, the water condenser 104 removes or condenses
the steam in the resultant hydrogen enriched gases and steam from
the water-gas shift reactor 78 prior to the hydrogen enriched gases
flowing into the depressurization subsystem 28. By removing the
steam from the hydrogen enriched gases and steam mixture, the gas
supplied to the depressurization subsystem 28 contains mostly
hydrogen enriched gas at a high pressure.
Table 2, below, illustrates a simulation of the concentrations of
carbon dioxide (CO.sub.2), water (H.sub.2O), hydrogen (H.sub.2),
carbon monoxide (CO) and dry based carbon monoxide (dry based CO)
in the simulated jet fuel after the jet fuel and steam mixture from
the conduit 90 flows through the water-gas shift reactor 78.
TABLE-US-00002 TABLE 2 steam/fuel Reactor dry based ratio T (C.)
CO2 % H2O % H2 % CO % CO % Fuel Content 5 250 16.23 31.76 51.46
0.45 0.66 After Water-Gas 5 200 16.46 31.53 51.69 0.22 0.32 Shift
Reactor 5 160 16.59 31.40 51.81 0.09 0.14 5 150 16.62 31.37 51.85
0.06 0.09
In Table 2, the steam inlet temperature in degrees Celsius (C) is
the temperature at the reactor inlet 92, and the reactor
temperature is a temperature of the housing 100 of the water-gas
shift reactor 78. The steam/fuel ratio is the ratio of steam to
fuel as mixed by the mixing valve 74. The values of the percentage
of carbon dioxide (CO.sub.2), water (H.sub.2O), hydrogen (H.sub.2),
carbon monoxide (CO) and dry based carbon monoxide (dry based CO)
are determined after the reformate from the reformer 76 has passed
through the water-gas shift reactor 78. In this simulation, the
water-gas shift reactor 78 is operating at a pressure of 1
atmosphere (atm). Thus, as illustrated in Table 1 and Table 2, the
use of the reformer 76 and the water-gas shift reactor 78 in series
results in a hydrogen-rich fuel stream or hydrogen enriched gases,
with reduced amounts of carbon monoxide (CO) and dry based carbon
monoxide (dry based CO).
The depressurization subsystem 28 is fluidly coupled to the water
condenser 104 and receives the hydrogen enriched gas from the water
condenser 104 via conduit 106. In one example, the depressurization
subsystem 28 includes a turbine 108 and a generator 110. The
turbine 108 can be coupled to and in communication with the conduit
106 to receive the higher pressure hydrogen enriched gases from the
water condenser 104. As the turbine 108 can comprise a conventional
turbine known to one skilled in the art, the turbine 108 will not
be discussed in great detail herein. Briefly, however, in one
example, the turbine 108 includes at least one rotor assembly 112
disposed in a casing, and the rotor assembly 112 is coupled to a
drive shaft 114. The high pressure hydrogen enriched gases from the
conduit 106 enters the casing of the turbine 108 and impinges on
the rotor assembly 112, causing the rotor assembly 112 to move or
rotate. The movement or rotation of the rotor assembly 112 causes
the rotation of the drive shaft 114, while also serving to
depressurize or reduce the pressure of the hydrogen enriched gases.
The depressurized or reduced pressure hydrogen enriched gases flow
from the turbine 108 to the fuel cell stack 16 via a conduit 116.
In one example, a pressure ratio of the turbine 108 ranges from
about 45:1 to about 24:1.
The generator 110 is coupled to the drive shaft 114 of the turbine
108. The generator 110 can comprise any suitable device for
converting the rotational mechanical energy of the drive shaft 114
into electrical energy. For example, the generator 110 can comprise
an electric generator 110 as known to one skilled in the art. The
electrical energy generated by the generator 110 can be transmitted
to one or more consumers 111 onboard the mobile platform 8, if
desired.
The gas supply system 14 supplies a gas to the cathode 58 of the
fuel cell stack 16. In one example, the gas is air, however, the
gas supply system 14 can comprise any suitable supply of gas for
use with the fuel cell stack 16. The gas supply system 14 includes
a blower 118 and the heat exchanger 72. The blower 118 draws gas in
and creates a current of the gas or a gas stream, which is directed
into a conduit 120. In one example, the blower 118 draws in gas
from air contained within the mobile platform 8, and/or draws in
air from the environment surrounding the mobile platform 8. For
example, in the embodiment of an aircraft, the blower 118 can draw
in air from the environment (ram air) or can draw in air from
within a fuselage. The blower 118 can comprise any suitable
conventional blower for creating and directing a current of air, as
known to one skilled in the art. As the blower 118 can be known in
the art, the blower 118 will not be discussed in great detail
herein. Briefly, however, the blower 118 can include a motor 122,
which can be responsive to one or more control signals from the
control system 18 to draw in gas and create the gas stream.
The gas stream from the conduit 120 can flow through the water
condenser 104. As will be discussed in further detail below, as the
gas stream in the conduit 120 can comprise cool or low temperature
gas, the flow of the gas through the water condenser 104 slightly
cools the fluid in the conduit 102 from the water-gas shift reactor
78, which causes the steam in the fluid to condense into water.
From the water condenser 104, the gas stream flows via a conduit
124 into the heat exchanger 72. The heat exchanger 72 transfers
heat from the exhaust gas in the conduit 70 to the gas stream from
the conduit 124 to heat the gas stream. As the heat exchanger 72
can comprise any suitable heat exchanger known in the art, the heat
exchanger 72 will not be discussed in great detail herein. The heat
exchanger 72 serves to warm the gas stream with the heat from the
exhaust gas of the steam generator or burner 38 prior to the gas
stream flowing into the cathode 58 of the fuel cell stack 16. A
conduit 126 fluidly couples the heat exchanger 72 to the cathode 58
of the fuel cell stack 16 to deliver the heated gas stream to the
fuel cell stack 16.
The water supply system 15 provides water for use by the steam
generator or burner 38. The water supply system 15 includes a water
source 130, a water pump 132 and the water condenser 104. The water
source 130 comprises any suitable source of water and in one
example, comprises a water tank. The water source 130 can be
located onboard the mobile platform 8, or can be located remote
from the mobile platform 8 and fluidly coupled to the mobile
platform 8 through suitable piping and couplings. The water
supplied by the water source 130 can be potable or non-potable.
The water pump 132 is fluidly coupled to the water source 130, and
is operable to pressurize or move water from the water source 130
to the steam generator or burner 38. As the water pump 132 can
comprise any suitable pump that moves or pressurizes a fluid as
known to one skilled in the art, the water pump 132 will not be
discussed in great detail herein. For example, the water pump 132
can comprise a rotary vane pump, a reciprocating pump, etc.
Briefly, the water pump 132 is operable to draw water from the
water source 130 via conduit 134 and deliver the water via conduit
136, with the water being heated by the water-gas shift reactor 78
before the water enters the steam generator or burner 38. It should
be noted that while two conduits 134, 136 are illustrated herein,
any arrangement of conduits and valves can be employed to enable
the water pump 132 to deliver water from the water source 130 to
the steam generator or burner 38. In one example, the water pump
132 is responsive to one or more control signals from the control
system 18 to draw the water from the water source 130.
The water condenser 104 comprises any suitable water condenser 104
for condensing water, as known to one skilled in the art.
Generally, the water condenser 104 is operated at a pressure
greater than ambient pressure, such as about 1.0 barG to about 10.0
barG. The water condenser 104 receives the higher temperature
hydrogen enriched gases and steam mixture from the conduit 102 and
the lower temperature gas from the conduit 120. The heat
differential between the hydrogen enriched gases and steam mixture
from the conduit 102 and the lower temperature gas from the conduit
120 causes the steam in the hydrogen enriched gases and steam
mixture to condense into water. The water condensed by the water
condenser 104 is directed via a conduit 138 to the water source
130, thereby recycling at least a portion of the water supplied by
the water supply system 15. The water condensed by the water
condenser 104 can travel through the conduit 138 to the water
source 130 via a gravity feed in one example; however, a second
water pump can be employed if desired, to assist in moving the
water from the water condenser 104 through the conduit 138. After
passing through the water condenser 104, the hydrogen enriched
gases, substantially depleted of steam, is directed to the turbine
108 via the conduit 106.
The fuel cell stack 16 is fluidly coupled to the turbine 108 to
receive the lower pressure hydrogen-rich gas or lower pressure
hydrogen enriched gases via the conduit 116, and is fluidly coupled
to the heat exchanger 72 to receive the heated gas via the conduit
126. The fuel cell stack 16 is operated at a low or ambient
pressure, thereby reducing the weight of the fuel cell stack 16 as
compared to a fuel cell stack operating at a higher pressure. As
the fuel cell stack 16 can comprise any suitable conventional fuel
cell stack 16 known in the art, the fuel cell stack 16 will not be
discussed in great detail herein. Briefly, in one example, the fuel
cell stack 16 can comprise a proton exchange or polymer electrolyte
membrane (PEM) fuel cell stack 16. It should be noted that the
example of a PEM fuel cell stack 16 is merely exemplary, as the
fuel cell stack 16 can comprise any suitable fuel cell stack 16,
including, but not limited to, a solid oxide fuel cell stack.
Generally, as is known in the art, in the example of a PEM fuel
cell stack, the fuel cell stack 16 includes the cathode 58 and the
anode 62, which are separated by an electrolyte, such as a polymer
electrolyte membrane 140. The cathode 58 includes a cathode inlet
58a and a cathode outlet 58b. The cathode 58 is in fluid
communication with the conduit 126 to receive the heated gas at the
cathode inlet 58a. The anode 62 includes an anode inlet 62a and an
anode outlet 62b. The anode inlet 62a is in fluid communication
with the turbine 108 to receive the lower pressure hydrogen
enriched gases via the conduit 116.
As known in the art, the polymer electrolyte membrane 140
facilitates an electrochemical reaction between oxygen in the gas
received at the cathode inlet 58a and the hydrogen or hydrogen
enriched gases received at the anode inlet 62a. The electrochemical
reaction results in electrical energy, which can be conducted from
the fuel cell stack 16 to the one or more consumers 111 located
downstream from the fuel cell stack 16 through suitable
transmission components as known to those skilled in the art. The
cathode outlet 58b receives water and remaining air from the
electrochemical reaction, and the anode outlet 62b receives the
remaining hydrogen enriched gases from the electrochemical
reaction. The cathode outlet 58b and the anode outlet 62b can be in
fluid communication with the steam generator or burner 38 via
conduits 56, 60 to ignite the exhaust gases from the fuel cell
stack 16.
The control system 18 controls the operation of the hybrid fuel
cell system 10. In one example, the control system 18 includes an
input device 150, one or more sensors 152 and a control module 154.
The input device 150 is manipulable by an operator of the hybrid
fuel cell system 10 to generate user input. In various embodiments,
the user input can include a command to start or stop the operation
of the hybrid fuel cell system 10. The input device 150 can be
implemented as a keyboard (not separately shown), a microphone (not
separately shown), a touchscreen layer associated with or as part
of a display 153, a switch, a button or other suitable device to
receive data and/or commands from the user. Of course, multiple
input devices 150 can also be utilized. The input device 150 can be
in communication with the control module 154 over a suitable
architecture or arrangement that facilitates the transfer of data,
commands, power, etc.
The one or more sensors 152 measure and observe various conditions
associated with the hybrid fuel cell system 10. It should be noted
that the one or more sensors 152 described and illustrated herein
are merely exemplary, as any number of sensors can be employed to
measure and observe conditions associated with the hybrid fuel cell
system 10. In one example, the one or more sensors 152 include a
current sensor 152a, a first temperature sensor 152b, a second
temperature sensor 152c, a third temperature sensor 152d, a fourth
temperature sensor 152e. The current sensor 152a measures and
observes a current output by the fuel cell stack 16 due to the
electrochemical reaction, and generates sensor signals based
thereon. The first temperature sensor 152b measures and observes a
temperature of the fuel cell stack 16, and generates sensor signals
based thereon. The second temperature sensor 152c measures and
observes a temperature of the steam generator or burner 38, and
generates sensor signals based thereon. The third temperature
sensor 152d measures and observes a temperature of the reformer 76,
and generates sensor signals based thereon. The fourth temperature
sensor 152e measures and observes a temperature of the water-gas
shift reactor 78, and generates sensor signals based thereon. The
one or more sensors 152 are in communication with the control
module 154 over a suitable architecture or arrangement that
facilitates the transfer of data, commands, power, etc.
The control module 154 receives the user input from the user input
device 150. Based on the user input, the control module 154 outputs
one or more control signals to the start-up valve 36 to move the
start-up valve 36 between the first, opened position and the
second, closed position. Based on the user input, the control
module 154 also outputs one or more control signals to the fuel
pump 22 to activate or deactivate the fuel pump 22. The control
module 154 also outputs the one or more control signals to the fuel
pump 22 to control the operation of the fuel pump 22 (e.g. the flow
rate of the fuel pump 22) based on the sensor signals. The control
module 154 outputs one or more control signals to the combustion
source 54 of the steam generator or burner 38 based on the user
input. Based on the sensor signals, the control module 154 outputs
one or more control signals to the mixing valve 74 to move the
mixing valve 74 between the first, opened position and the second,
closed position. Based on the sensor signals or the user input, the
control module 154 outputs one or more control signals to the water
pump 132 to activate or deactivate the water pump 132. Based on the
sensor signals, the control module 154 outputs one or more control
signals to the blower 118 to activate or deactivate the blower
118.
In order to assemble the hybrid fuel cell system 10, the fuel
source 20 is fluidly coupled to the fuel pump 22, and the fuel pump
22 is fluidly coupled to the mixing valve 74 (via the conduit 34)
and the start-up valve 36 (via the conduit 32). The start-up valve
36 is fluidly coupled to the steam generator or burner 38 (via the
conduit 40) to generate steam. The steam generator or burner 38 is
fluidly coupled to the water-gas shift reactor 78 to receive heated
water (via the conduit 64). The water from the water-gas shift
reactor 78 is circulated in the steam generator or burner 38 via
conduit 66 to generate steam, and the steam generator or burner 38
is fluidly coupled to the mixing valve 74 (via the conduit 68). The
exhaust of the steam generator or burner 38 is fluidly coupled to
the heat exchanger 72 to supply the heat exchanger 72 with
heat.
The mixing valve 74 is fluidly coupled to the reformer 76 (via the
conduit 80). The reformer 76 is fluidly coupled to the water-gas
shift reactor 78 (via the conduit 90), and optionally, fluidly
coupled to the air source via air inlet 84. The water-gas shift
reactor 78 is fluidly coupled to the water source 130 via the water
pump 132 such that water can be circulated through the water-gas
shift reactor 78 via the conduit 95. The water-gas shift reactor 78
is also fluidly coupled to the water condenser 104 (via the conduit
102). The water condenser 104 is fluidly coupled to the turbine 108
(via the conduit 106), and fluidly coupled to the water source 130
(via the conduit 138) to enable recirculation or recycling of the
water condensed by the water condenser 104. The turbine 108 is
coupled to the generator 110, and fluidly coupled to the anode 62
of the fuel cell stack 16.
The blower 118 is fluidly coupled to the water condenser 104 (via
the conduit 120) to provide cooled gas for condensing the water in
the fuel steam mixture provided into the water condenser 104 by
conduit 106. The water condenser 104 is also fluidly coupled to the
heat exchanger 72 (via the conduit 124) to provide the cool gas to
the heat exchanger 72. The heat exchanger 72 heats the cooled gas,
and is fluidly coupled to the cathode 58 of the fuel cell stack 16
to provide the heated gas to the cathode 58 (via the conduit
126).
Upon receipt of a command to start-up the hybrid fuel cell system
10, such as a command received via the user input device 150, the
control module 154 outputs the one or more control signals to the
start-up valve 36 and the fuel pump 22 to provide fuel from the
fuel source 20 to the steam generator or burner 38. The control
module 154 also outputs the one or more control signals to the
water pump 132 to move water from the water source 130 through the
water-gas shift reactor 78 and into the steam generator or burner
38 to generate steam. The control module 154 outputs the one or
more controls signals to the combustion source 54 to activate the
steam generator or burner 38 to ignite the fuel provided by the
fuel source 20 via the start-up valve 36 and the fuel pump 22. By
burning the fuel provided via the start-up valve 36 initially, the
steam generator or burner 38 starts generating steam from the water
supplied by the water pump 132. The initial steam generation is
used to bring the hybrid fuel cell system 10 to a desired operating
temperature, as required by the particular fuel cell stack 16
employed by the fuel cell system 10. In the example of a PEM fuel
cell stack 16, the desired operating temperature ranges from about
80 degrees Celsius (C) to about 100 degrees Celsius (C).
When the steam and the reforming subsystem 26 are heated to a
sufficient or desired temperature by the steam generator or burner
38, the control module 154 outputs the one or more control signals
to the start-up valve 36 to move the start-up valve 36 from the
first, opened position to the second, closed position. The control
module 154 also outputs the one or more control signals to the
mixing valve 74 to move the mixing valve 74 from the second, closed
position to the first, opened position. The control module 154 also
outputs the one or more control signals to the motor 122 of the
blower 118 to operate the blower 118 to create the gas stream. With
the mixing valve 74 in the first, opened position, the fuel from
the fuel source 20 mixes with the hot steam from the steam
generator or burner 38 and flows into the reformer 76. In the
reformer 76, the fuel and steam mixture reacts with the catalysts
88a to convert the fuel into hydrogen (H.sub.2), carbon monoxide
(CO) and carbon dioxide (CO.sub.2). From the reformer 76, the
hydrogen enriched gases and steam mixture flows into the water-gas
shift reactor 78. The hydrogen enriched gases and steam mixture
reacts with the catalysts in the water-gas shift reactor 78 to
generate additional hydrogen (H.sub.2), resulting in a hydrogen
enriched gases and steam mixture exiting the water-gas shift
reactor 78.
From the water-gas shift reactor 78, the hydrogen enriched gases
and steam mixture flows through the water condenser 104, and the
steam in the hydrogen enriched gases and steam mixture is condensed
into water. The water condensed by the water condenser 104 flows
back to the water source 130, thereby recycling the water employed
by the hybrid fuel cell system 10. From the water condenser 104,
the hydrogen enriched gases flow into the turbine 108, where the
pressure of the hydrogen enriched gases is reduced. By reducing the
pressure of the hydrogen enriched gases, the fuel cell stack 16 is
operated at an ambient operating pressure. From the turbine 108,
the hydrogen enriched gases flow into the anode 62 of the fuel cell
stack 16.
The blower 118 creates the gas stream for use by the cathode 58 of
the fuel cell stack 16. With the motor 122 of the blower 118
activated, the blower 118 moves or creates the gas stream, which
flows through the water condenser 104 to aid in condensing the
steam in the hydrogen enriched gases and steam mixture. From the
water condenser 104, the gas stream flows into the heat exchanger
72, and the gas stream is heated by the heated exhaust gases of the
steam generator or burner 38. From the heat exchanger 72, the
heated gas flows into the cathode 58 of the fuel cell stack 16.
The electrochemical reaction between the heated gas at the cathode
58 and the hydrogen enriched gases at the anode 62 generates
electrical energy, which is transmitted to the one or more
consumers 111. The rotation of the turbine 108 also generates
electrical energy via the generator 110, which is also transmitted
to the one or more consumers 111. The resultant exhaust gases from
the electrochemical reaction at the fuel cell stack 16 flow to the
steam generator or burner 38, and the steam generator or burner 38
ignites these gases to aid in generating high temperature
steam.
With reference now to FIG. 2, a hybrid fuel cell system 200 is
shown. As the hybrid fuel cell system 200 can be similar to the
hybrid fuel cell system 10 discussed with regard to FIG. 1, only
the differences between the hybrid fuel cell system 10 and the
hybrid fuel cell system 200 will be discussed in detail herein,
with the same reference numerals used to denote the same or
substantially similar components. With reference to FIG. 2, the
hybrid fuel cell system 200 includes a fuel supply system 202, the
gas supply system 14, the water supply system 15, the fuel cell
stack 16 and the control system 18. Although the figures shown
herein depict an example with certain arrangements of elements,
additional intervening elements, devices, features, or components
may be present in an actual embodiment. It should also be
understood that FIG. 2 is merely illustrative and may not be drawn
to scale.
With continued reference to FIG. 2, the fuel supply system 202 is
in fluid communication with the fuel cell stack 16 to provide the
fuel cell stack 16 with hydrogen enriched gases. In one example,
the fuel supply system 202 includes the fuel source 20, the fuel
pump 22, the start-up subsystem 24, the reforming subsystem 26 and
a depressurization subsystem 204.
The depressurization subsystem 204 is fluidly coupled to the water
condenser 104 of the water supply system 15 and receives the
hydrogen enriched gases from the water condenser 104 via the
conduit 106. In this example, the depressurization subsystem 204
includes a pressure regulator valve 206. The pressure regulator
valve 206 is coupled to and in communication with the conduit 106
to receive the higher pressure hydrogen enriched gases from the
water condenser 104. As the pressure regulator valve 206 can
comprise a conventional pressure regulator valve known to one
skilled in the art, the pressure regulator valve 206 will not be
discussed in great detail herein. Briefly, however, the pressure
regulator valve 206 reduces the high pressure hydrogen enriched
gases to a lower pressure hydrogen enriched gases for use in the
fuel cell stack 16. By reducing the pressure of the hydrogen
enriched gases, the fuel cell stack 16 is operable at a reduced or
ambient pressure. The depressurized or reduced pressure hydrogen
enriched gases flow from the pressure regulator valve 206 to the
fuel cell stack 16 via the conduit 116. In one example, a pressure
ratio of the pressure regulator valve 206 ranges from about 45:1 to
about 2:1.
As the hybrid fuel cell system 200 can operate substantially
similar to the hybrid fuel cell system 10 discussed above with
regard to FIG. 1, the operation of the hybrid fuel cell system 200
will not be discussed in great detail herein. Briefly, however, the
pressure regulator valve 206 is in fluid communication with the
water condenser 104 (via the conduit 106) to receive the high
pressure hydrogen enriched gases, and is in fluid communication
with the anode 62 of the fuel cell stack 16 (via the conduit 116)
to deliver low pressure hydrogen enriched gases to the fuel cell
stack 16. In this regard, the hydrogen enriched gases from the
water condenser 104 flows via conduit 106 into the pressure
regulator valve 206. The pressure regulator valve 206 reduces the
pressure of the hydrogen enriched gases to a lower pressure, and
the lower pressure hydrogen enriched gases flows from the pressure
regulator valve 206 via the conduit 116 to the anode 62 of the fuel
cell stack 16.
With reference now to FIG. 3, a hybrid fuel cell system 300 is
shown. As the hybrid fuel cell system 300 can be similar to the
hybrid fuel cell system 10 discussed with regard to FIG. 1, only
the differences between the hybrid fuel cell system 10 and the
hybrid fuel cell system 300 will be discussed in detail herein,
with the same reference numerals used to denote the same or
substantially similar components. With reference to FIG. 3, the
hybrid fuel cell system 300 includes a fuel supply system 302, the
gas supply system 14, the water supply system 15, the fuel cell
stack 16 and the control system 18. Although the figures shown
herein depict an example with certain arrangements of elements,
additional intervening elements, devices, features, or components
may be present in an actual embodiment. It should also be
understood that FIG. 3 is merely illustrative and may not be drawn
to scale.
With continued reference to FIG. 3, the fuel supply system 302 is
in fluid communication with the fuel cell stack 16 to provide the
fuel cell stack 16 with hydrogen enriched gases. In this example,
the fuel supply system 302 includes the fuel source 20, the fuel
pump 22, the start-up subsystem 24, the reforming subsystem 26 and
a depressurization subsystem 304.
The depressurization subsystem 304 is fluidly coupled to the water
condenser 104 and receives the hydrogen enriched gases from the
water condenser 104 via the conduit 106. In one example, the
depressurization subsystem 304 includes a heat exchanger and water
condenser assembly 306, the turbine 108 and the generator 110. The
heat exchanger and water condenser assembly 306 includes a heat
exchanger 306a and a water condenser 306b operating together to
remove additional water from the hydrogen enriched gases provided
by the conduit 106. As the heat exchanger 306a and the water
condenser 306b can comprise any suitable heat exchanger and water
condenser known in the art, the heat exchanger 306a and the water
condenser 306b will not be discussed in great detail herein. The
heat exchanger and water condenser assembly 306 is in fluid
communication with the conduit 106 to receive the hydrogen enriched
gases from the water condenser 104, and is in fluid communication
with the turbine 108 to receive the lower pressure hydrogen
enriched gases via conduit 308. The lower pressure hydrogen
enriched gases from the turbine 108 is cooler, and serves to
condense additional water from the high pressure hydrogen enriched
gases provided by the conduit 106. The high pressure hydrogen
enriched gases, after passing through the heat exchanger and water
condenser assembly 306 flow into the turbine 108 via conduit 312.
The water condenser 306b is in fluid communication with the water
source 130 so that the water condensed by the water condenser 306b
flows back to the water source 130 via conduit 310. After passing
through the water condenser 306b, the lower pressure hydrogen
enriched gases flow into the anode 62 of the fuel cell stack 16 via
the conduit 116.
As the hybrid fuel cell system 300 can operate substantially
similar to the hybrid fuel cell system 10 discussed above with
regard to FIG. 1, the operation of the hybrid fuel cell system 300
will not be discussed in great detail herein. Briefly, however, the
heat exchanger and water condenser assembly 306 is in fluid
communication with the water condenser 104 (via the conduit 106) to
receive the high pressure hydrogen enriched gases, and is in fluid
communication with the turbine 108 (via the conduit 308 and 314) to
receive the low pressure hydrogen enriched gases. The heat
exchanger and water condenser assembly 306 is also in fluid
communication with the anode 62 of the fuel cell stack 16 (via the
conduit 116) to deliver low pressure hydrogen enriched gases to the
fuel cell stack 16 and is in fluid communication with the water
source 130 (via the conduit 310, 138) to provide condensed water to
the water source 130.
The high pressure hydrogen enriched gases from the water condenser
104 flows via conduit 106 into the heat exchanger and water
condenser assembly 306. The heat exchanger and water condenser
assembly 306 uses the lower pressure hydrogen enriched gases from
the turbine 108 to condense water from the higher pressure hydrogen
enriched gases, and the condensed water is recycled back to the
water source 130. After passing through the heat exchanger and
water condenser assembly 306, the high pressure hydrogen enriched
gases flow through the turbine 108, which reduces the pressure of
the hydrogen enriched gases to a lower pressure, and the lower
pressure hydrogen enriched gases flow from the turbine 108 via the
conduit 308 to the heat exchanger and water condenser assembly 306.
From the heat exchanger and water condenser assembly 306, the lower
pressure hydrogen enriched gases flow into the anode 62 of the fuel
cell stack 16 via the conduit 116.
While at least one exemplary embodiment has been presented in the
foregoing detailed description, it should be appreciated that a
vast number of variations exist. It should also be appreciated that
the exemplary embodiment or exemplary embodiments are only
examples, and are not intended to limit the scope, applicability,
or configuration of the disclosure in any way. Rather, the
foregoing detailed description will provide those skilled in the
art with a convenient road map for implementing the exemplary
embodiment or exemplary embodiments. It should be understood that
various changes can be made in the function and arrangement of
elements without departing from the scope of the disclosure as set
forth in the appended claims and the legal equivalents thereof.
* * * * *